Hemoglobin

Measured in g/dL

The amount of oxygen-carrying protein in your blood — usually the most informative single red-cell number, though it still shifts with hydration.

What it is

Hemoglobin is the iron-containing protein inside red blood cells that actually binds and carries oxygen, and this test measures how much of it is in a given volume of blood. It's typically the number clinicians lean on most when looking at whether your blood is carrying oxygen well, and it's read alongside hematocrit and the red cell indices for context. Normal ranges differ by sex and altitude, and the value moves with hydration, pregnancy, and lab-to-lab measurement differences, so small shifts between draws are common and the trend over time usually matters more than one reading.

Typical range

  • Male13.5–17.5 g/dL
  • Female12.0–15.5 g/dL

Source · StatPearls (NCBI Bookshelf NBK604207) (2024)

Reference ranges vary between laboratories, and what is normal for you depends on your own history. Your own lab’s range is the one printed on your report.

Worth asking your clinician

  • Is my hemoglobin where you'd expect it to be for someone with my age, sex, and health history?
  • How does this compare to my previous hemoglobin results — is there a trend worth watching?
  • Would any additional context or follow-up testing be helpful here, or is this something to simply recheck at my next visit?